Yep, the sum of six Math.random() will start to look a bit like a normal distribution, while Math.random()*6 will stay flat.
Even crazier: the sum of six (Math.random()>.5)?0:1 will also look a bit like a normal distribution, rather than just 0 50% of the time and 6 50% of the time.
Central Limit Theorem eats distributions of all shapes and sizes and shits gaussians. That's why you see normal distributions everywhere.